Key Words:LITHIUM STORAGE; XPS SPECTRA; OXIDE; ANODE

Abstract:Rechargeable aluminum batteries (RABs) are an emerging energy storage device owing to the vast Al resources, low cost, and high safety. However, the poor cyclability and inferior reversible capacity of cathode materials have limited the enhancement of RABs performance. Herein, a high configurational entropy strategy is presented to improve the electrochemical properties of RABs for the first time. The high-entropy (Fe, Mn, Ni, Zn, Mg)3O4 cathode exhibits an ultra-stable cycling ability (109 mAh g-1 after 3000 cycles), high specific capacity (268 mAh g-1 at 0.5 A g-1), and rapid ion diffusion. Ex situ characterizations indicate that the operational mechanism of (Fe, Mn, Ni, Zn, Mg)3O4 cathode is mainly based on the redox process of Fe, Mn, and Ni. Theoretical calculations demonstrate that the oxygen vacancies make a positive contribution to adjusting the distribution of electronic states, which is crucial for enhancing the reaction kinetics at the electrolyte and cathode interface. These findings not only propose a promising cathode material for RABs, but also provide the first elucidation of the operational mechanism and intrinsic information of high-entropy electrodes in multivalent ion batteries. A novel high-entropy material, (Fe, Mn, Ni, Zn, Mg)3O4, is synthesized and extensively characterized. Meanwhile, this work provides a systematic and comprehensive exploration of the electrochemical performance, operating mechanism, and internal electronic information of high-entropy oxides in multivalent rechargeable aluminum batteries for the first time.image

Volume:20

Issue:5

Translation or Not:no